<?php

/**
 * "Inline" diff renderer.
 *
 * This class renders diffs in the Wiki-style "inline" format.
 *
 * $Horde: framework/Text_Diff/Diff/Renderer/inline.php,v 1.16 2006/01/08 00:06:57 jan Exp $
 *
 * @author  Ciprian Popovici
 * @package Text_Diff
 */
class Text_Diff_Renderer_inline extends Text_Diff_Renderer {

		/**
 		* Number of leading context "lines" to preserve.
 		*/
		var $_leading_context_lines = 10000;

		/**
 		* Number of trailing context "lines" to preserve.
 		*/
		var $_trailing_context_lines = 10000;

		/**
 		* Prefix for inserted text.
 		*/
		var $_ins_prefix = '<ins>';

		/**
 		* Suffix for inserted text.
 		*/
		var $_ins_suffix = '</ins>';

		/**
 		* Prefix for deleted text.
 		*/
		var $_del_prefix = '<del>';

		/**
 		* Suffix for deleted text.
 		*/
		var $_del_suffix = '</del>';

		/**
 		* Header for each change block.
 		*/
		var $_block_header = '';

		/**
 		* What are we currently splitting on? Used to recurse to show word-level
 		* changes.
 		*/
		var $_split_level = 'words';

		function _blockHeader($xbeg, $xlen, $ybeg, $ylen)
		{
				return $this->_block_header;
		}

		function _startBlock($header)
		{
				return $header;
		}

		function _lines($lines, $prefix = ' ', $encode = true)
		{
				if ($encode) {
						array_walk($lines, array(&$this, '_encode'));
				}

				if ($this->_split_level == 'words') {
						return implode('', $lines);
				} else {
						return implode("\n", $lines) . "\n";
				}
		}

		function _added($lines)
		{
				array_walk($lines, array(&$this, '_encode'));
				$lines[0] = $this->_ins_prefix . $lines[0];
				$lines[count($lines) - 1] .= $this->_ins_suffix;
				return $this->_lines($lines, ' ', false);
		}

		function _deleted($lines, $words = false)
		{
				array_walk($lines, array(&$this, '_encode'));
				$lines[0] = $this->_del_prefix . $lines[0];
				$lines[count($lines) - 1] .= $this->_del_suffix;
				return $this->_lines($lines, ' ', false);
		}
		
		function _context($lines)
		{
				return "<!-- Start context -->\n<tr><td></td><td class=\"diff-context\">".$this->_lines($lines).'</td></tr>'."\n<!-- End context -->\n\n";
		}

		function _changed($orig, $final)
		{
				/* If we've already split on words, don't try to do so again - just
 				* display. */
				if ($this->_split_level == 'words') {
						$prefix = '';
						while ($orig[0] !== false && $final[0] !== false &&
 									substr($orig[0], 0, 1) == ' ' &&
 									substr($final[0], 0, 1) == ' ') {
								$prefix .= substr($orig[0], 0, 1);
								$orig[0] = substr($orig[0], 1);
								$final[0] = substr($final[0], 1);
						}
						return $prefix . $this->_deleted($orig) . $this->_added($final);
				}

				$text1 = implode("\n", $orig);
				$text2 = implode("\n", $final);

				/* Non-printing newline marker. */
				$nl = "\0";

				/* We want to split on word boundaries, but we need to
 				* preserve whitespace as well. Therefore we split on words,
 				* but include all blocks of whitespace in the wordlist. */
				$diff = &new Text_Diff($this->_splitOnWords($text1, $nl),
 															$this->_splitOnWords($text2, $nl));

				/* Get the diff in inline format. */
				$renderer = &new Text_Diff_Renderer_inline(array_merge($this->getParams(),
 																															array('split_level' => 'words')));

				/* Run the diff and get the output. */
				return str_replace($nl, "\n", $renderer->render($diff)) . "\n";
		}

		function _splitOnWords($string, $newlineEscape = "\n")
		{
				$words = array();
				$length = strlen($string);
				$pos = 0;

				while ($pos < $length) {
						// Eat a word with any preceding whitespace.
						$spaces = strspn(substr($string, $pos), " \n");
						$nextpos = strcspn(substr($string, $pos + $spaces), " \n");
						$words[] = str_replace("\n", $newlineEscape, substr($string, $pos, $spaces + $nextpos));
						$pos += $spaces + $nextpos;
				}

				return $words;
		}

		function _encode(&$string)
		{
				$string = htmlspecialchars($string);
		}

}
